Re: SEALED vs PORTED (basic info.)

Originally Posted by dodgemyavenger

sorry to rephraze the question that i asked.... usually when a subwoofer is mounted the rear of the sub, the magnet is inside of the box. if the subwoofer is instead mounted with the magnet on the outside of the box with the cone facing the inside is the performance of the subwoofer changed? by performance i mean sq, and frequencies and power handling. are certain subs not even designed to be mounted this way? if so where can i find this information i already checked the manufacturer's website.

Performance is not changed. You can do it with any subwoofer.

Just keep in mind that it will have an effect on the box size, however.

Re: SEALED vs PORTED (basic info.)

Originally Posted by jimmyjames1700

Also, keep in mind that the real world vented enclosure will tune lower than predicted. That Kicker when loaded in an enclosure and begins having real power touch its VC, the box tuning will fall to somewhere near 34-35 Hz.

When designing an enclosure for a super sub, say a Titanium or W7, you must design the box with tuning about 6-7 Hz higher than desired. If you ever modeled the 32 Hz tuned vented enclosure for the W7 on JL's website, you will see that it is tuned at 38 Hz.

Wondering what evidence you have for this? Seems like that defeats the purpose of tuning a box at all, unless you are talking about cabin gains?

In fact all W7's, or other supersubs for that matter, need to be designed with box tuning that much higher (6-7Hz).

When we first started designing and building custom vented boxes for the W7's we wondered why the tuning always ended up way lower than predicted. In fact, the first 32Hz vented box we designed and built for a customers 12W7 ended being tuned at 26 Hz! It definitely perked my curiousity.

So a after a quick call to Hector at JL we learned that simple port formulas or programs like BassBox Pro cannot accurately predict what a sub/box combination will do once current starts flowing through a subs Voice Coil. Thats why the big shot's use programs like Leap which take into account many other factors. Basically T/S parameters and box calculators just get you into the ball park.

I've seen it first hand. All vented sub enclosures designed with port formulas our say BassBox Pro will tune lower than predicted. Most will tune about 10%-15% lower than predicted, with the supersubs usually being significantly more.

Re: SEALED vs PORTED (basic info.)

when i do calculations do i have to get them into the same units? For example, for Vd i have to do Sd x Xmax, and with the info i have it is 13.35 mm for Sd and 467.59 cm squared for the Xmax, do i have to put these both into mm? or cm? or what?

Re: SEALED vs PORTED (basic info.)

Hey, JL Audio 12w3v2 D4

I've been reccomended to put it in a sealed box because I a) drive a scion tC (read cheap hatchback) with limited space, and b) listen to a _broad_ range of music. I believe JL reccomends 1-1.5 cu.ft for a sealed enclosure.

Re: SEALED vs PORTED (basic info.)

I want to build a bandpass box 4th order for a DUAL XiNC110 woofer. It maxes out at 600 watts and has a 50-150 watt RMS range...the frequency range for it is around 30hz-220hz i believe. What I need to know is what frequency to tune the box I wanna build for rock/hard rock sound. This right now is the only thing holding me back once I figure that out I can use a design program and figure out the dimensions it should be and everything else. The dimensions I'm hoping to use are 15"W,13.5"H,12"D so if I use those dimensions what could I do to tune my box to a flatter frequency? I made a thread in this forum a while earlier but I'm desperate for a solution quickly so I can get started ASAP so some help would definatly be appreciated. Thanks to anyone who does reply to this with some useful info

I feel like when im bumpin once it gets dark....the street lights often go out. I was driving home the other night and like 3 street lights went out in like 15 minutes.
Does this happen a lot to any of you??
Also if you have had the twix ice cream......isnt it amazing!

I feel like when im bumpin once it gets dark....the street lights often go out. I was driving home the other night and like 3 street lights went out in like 15 minutes.
Does this happen a lot to any of you??
Also if you have had the twix ice cream......isnt it amazing!